1. Field of the Invention
The present invention relates to a cable broadcast program receiver and transmitter, and more particularly, to a digital cable TV receiver, a diagnostic method for the digital cable TV receiver, and a data structure of a DVI status report.
2. Discussion of the Related Art
Generally, a Digital Visual Interface (DVI) is a transmission standard established by a consortium called the Digital Display Working Group (DDWG), which has been created by a group of leaders in the computer industry. The DVI is used to digitally connect a personal computer (PC) to a flat monitor. More specifically, the DVI is a standard for digitally connecting signals exchanged between the PC and the monitor. The DVI has mainly been adopted to peripheral devices that are used by being connected to a PC, such as personal computers, office projectors, general plasma displays, electric boards. And, recently, the DVI has also been adopted in digital television (TV) receivers and cable digital television (TV) receivers. Before the DVI standard was developed, digital signals were exchanged by a complicated process. First, the PC creates digital data. Then, even though the digital display device is capable of receiving digital data, the digital data transmitted from the PC is converted to analog data, which is converted back to digital data and then transmitted to the digital display device. Therefore, in order to avoid such a complicated process, the DVI standard has been developed to allow the digital data created from the PC to be digitally transmitted directly to the display device through a cable. In the DVI standard, digital broadcast signals that are not compressed are transmitted in a single direction.
Meanwhile, a cable broadcast system broadly includes a cable broadcast station and a cable broadcast program receiver (or digital cable TV receiver). Herein, the cable broadcast station transmits cable broadcast programs, and the cable broadcast program receiver receives the transmitted cable broadcast program. The cable broadcast station may be referred to a SO head-end or a MSO head-end. The SO refers to a System Operator (SO) (i.e., the Local Cable TV System Operator), and the MSO refers to a Multiple System Operator (MSO), which is a group of SO.
Moreover, the cable broadcast program receiver adopts an open cable, wherein a Point of Deployment (POD) module including a Conditional Access (CA) system is separated (or detached) from the main body. For example, the POD module uses a Personal Computer Memory Card International Association (PCMCIA) card which can be mounted onto and separated from a main body slot of the cable broadcast program receiver. Therefore, the POD module may also be referred to as a cable card, and the main body, wherein the POD module is inserted, may also be referred to as a host. In other words, a combination of the POD module and the main body is referred to as the cable broadcast program receiver. Herein, the host may be connected to other peripheral devices (e.g., a DVD player, a digital camera/camcorder, a set-top box, etc.) through a DVI link. And, as shown in FIG. 1 to FIG. 3, at least one or more peripheral devices may be connected. More specifically, when at least one DVI terminal/port (or a plurality of DVI terminals/ports) is provided by the host, at least one peripheral device (or a plurality of peripheral devices) may be simultaneously connected to the host.
Referring to FIG. 1 to FIG. 3, one of a Digital Built-in TV and a Digital Ready TV corresponds to the host. FIG. 1 illustrates an example of the host being connected to a peripheral device through a single DVI link. More specifically, an Output port of a set-top box (or a DVD Player) is connected to a DVI Input port of the host. FIG. 2 illustrates an example of the host being connected to a plurality of peripheral devices through a plurality of DVI links, wherein a plurality of DVI Input ports is provided by the host. Referring to FIG. 2, a DVI Output port of the Set Top box is connected to a first DVI Input port of the host, and, simultaneously, a DVI Output port of a DVD Player is connected to a second DVI Input port of the host. Finally, FIG. 3 illustrates an example of both DVI Input/Output ports being provided in a random peripheral device. More specifically, both DVI Input/Output ports are provided in a Set Top box. Referring to FIG. 3, the DVI Output port of the Set Top box is connected to the DVI Input port of the host, and the DVI Output port of a DVD Player (or another peripheral device) is connected to the Input port of the Set Top box.
Meanwhile, in an open cable standard, wherein the POD module is separated from the main body, as described above, the host has a diagnostic function that can monitor each status of the host. For example, in Host-POD interface standard, a Generic Diagnostic Protocol is defined in a host-POD resource layer. More specifically, when the host receives a request for verifying and reporting the DVI status from the POD module through the Generic Diagnostic Protocol, the host verifies the DVI status and creates a syntax (DVI Status Report Syntax) so as to report the verified DVI status to the POD module.
However, according to the DVI Status Report Syntax, when a plurality of peripheral devices is simultaneously connected to the host through the DVI port, as shown in FIG. 2 and FIG. 3, only the DVI link status information for one port can be transmitted to the POD module, and the DVI link status information for the remaining ports cannot be transmitted to the POD module. Furthermore, when DVI Input/Output ports both exist within a peripheral device and when the host and another peripheral device is connected to the corresponding Input/Output ports, as shown in FIG. 3, only the DVI link status information for one port can be transmitted to the POD module, and the DVI link status information for the remaining ports cannot be transmitted to the POD module.